Semiconductor device and method for fabricating the same

Abstract

The semiconductor device comprises a capacitor formed over a semiconductor substrate 10 and including a lower electrode 32 , a dielectric film 34 formed over the lower electrode and an upper electrode 36 formed over the dielectric film, a first insulation film 42 formed over the semiconductor substrate and the capacitor, a first interconnection 48 formed over the first insulation film and electrically connected to the capacitor, a first hydrogen diffusion preventive film 50 for preventing the diffusion of hydrogen formed over the first insulation film, covering the first interconnection, a second insulation film 58 formed over the first hydrogen diffusion preventive film and having the surface planarized, a third insulation film 62 formed over the second insulation film, a second interconnection 70 b formed over the third insulation film, and a second hydrogen diffusion preventive film 72 for preventing the diffusion of hydrogen formed on the third insulation film, covering the second interconnection. Since the second hydrogen diffusion preventive film positioned above the capacitor is planarized, the dielectric film is surely prevented from being reduced with hydrogen.

1. A semiconductor device fabricating method comprising:
 forming over a semiconductor substrate a capacitor including a lower electrode, a dielectric film formed over the lower electrode and an upper electrode formed over the dielectric film; 
 forming a first insulation film over the semiconductor substrate and the capacitor; 
 forming a contact hole in the first film down to the capacitor; 
 forming over the first insulation film a first interconnection electrically connected to the capacitor via the contact hole; 
 forming over the first insulation film a first hydrogen diffusion preventive film for preventing the diffusion of hydrogen, covering the first interconnection; 
 forming a second insulation film over the first hydrogen diffusion preventive film; 
 polishing the surface of the second insulation film to planarize the surface of the second insulation film; 
 forming a third insulation film over the second insulation film; 
 forming a second interconnection over the third insulation film; and 
 forming over the third insulation film a second hydrogen diffusion preventive film for preventing the diffusion of hydrogen, covering the second interconnection, 
 wherein in the forming the second interconnection, a solid conduction film is further formed at least above the capacitor, 
 in the forming the second hydrogen diffusion preventive film, the second hydrogen diffusion preventive film is formed, covering the solid conduction film, 
 the first hydrogen diffusion preventive film and the second hydrogen diffusion preventive film are formed of metal oxide, 
 said method further comprises forming a silicon nitride film over the second hydrogen diffusion preventive film, and 
 forming a polyimide film over the silicon nitride film. 
 
     
     
       2. A semiconductor device fabricating method according to  claim 1 , further comprising, after the forming the first insulation film and before the forming the first hydrogen diffusion preventive film, making thermal processing. 
     
     
       3. A semiconductor device fabricating method according to  claim 1 , further comprising, after the forming the second insulation film and before the forming the third insulation film, making thermal processing. 
     
     
       4. A semiconductor device fabricating method according to  claim 1 , further comprising, after the forming the third insulation film and before the forming the second hydrogen diffusion preventive film, making thermal processing.